1. Field of the Invention
This invention relates generally to the treatment of nutrient-rich water. More particularly, it relates to a physical-chemical and microbiological process and apparatus to remove nitrogen compounds and phosphorous compounds from bodies of water.
2. BACKGROUND OF THE ART
Water typically contains a variety of contaminants. For example, run-off from agricultural land contains manure, fertilizers, and pesticides. Effluent from municipal secondary treatment sewage plants contains nitrogen and phosphorous compounds. Moreover, phosphorous and nitrogen compounds build up over time in aquaculture and aquarium waters. The above examples of contaminated water all have in common relatively high nutrient levels containing phosphorous compounds, nitrogen compounds, and other minerals. These type of waters are receiving a greater scrutiny for their deleterious effects on the environment.
A number of methods are known for dealing with organic and inorganic contaminants in wastewater. For example, U.S. Pat. Nos. 3,957,632; 3,980,556; 4,500,429; 4,664,803; 4,708,207; 4,919,815; and 4,931,183 disclose the use of biological treatment to remove carbonaceous and nitrogen compounds from wastewater. The disclosure of the above patents, and of all other articles and patents recited herein, are incorporated by reference as if fully set forth herein.
Other processes use vegetation and soil to remove wastewater contaminants, sometimes in conjunction with biological treatment. See, for example, U.S. Pat. Nos. 681,884; 5,137,625; and 5,156,741. Finally, U.S. Pat. No. 5,106,504 discloses an artificial water impoundment system planted in aquatic vegetation to remove pollutants from run-off water. However, much remains to be done in economically and compactly treating waters which are high in nutrient content.
As a result, a need exists for a low cost treatment system for handling water having a high nutrient content. Such a system would be useful for treating agricultural run-off, aquaculture and aquarium systems, swamp and canal water contamination, and effluent from municipal secondary sewage treatment plants.